采动敏感型底板岩巷失稳机理模拟分析

Simulation on Instability Mechanism of Mining Induced Sensitive Floor Roadway

近年来任楼煤矿随着矿井开采强度不断增大和采深增加,岩巷的有效维护已成为制约矿井安全生产的突出问题.针对该矿底板跨采巷道工程地质特点,通过相似模拟、数值模拟手段研究了巷道变形失稳的机理,并从巷道的布置层位、围岩性质及受采动影响状况等方面分析了巷道变形破坏的原因.研究结果认为:巷道对采动影响敏感,影响距离大于140 m;两帮与肩角是该类巷道变形破坏的起始部位.因此有效改善该弱结构部位的围岩体力学性能,从而使支护体与围岩共同作用形成有效承载结构,是治理采动敏感型底板巷道的主要技术途径,并提出了弱结构部位进行加强的非均匀支护技术.以该矿Ⅱ1回风下山工程实践进行了现场试验,结果表明,该下山在受上部煤层开采影响时,围岩变形量得到了有效控制,为矿井的安全生产创造了条件,取得了良好的技术经济效益.

With the increase of mining intensity and depth, the support of rock roadways has become a protruding problem affecting the safety production. Aimed at the engineering geological characteristics of the floor roadway, the instability mechanism of the roadway is studied by similar material simulation and numerical modeling. The layout of roadway, property of surrounding rocks, and the influence of mining are considered in analyzing the failure reasons of roadways. The result indicates that the roadway is sensitive to mining induced effect, with the influence distance being more than 140m. The shoulders and the two sides of roadway is original failure position. So, to effectively improve mechanical property of the surrounding rock in these weak positions to form an joint structure of support and surrounding rocks is the main technical approach for controlling the mining sensitive roadway. The in-situ test carried out in Ⅱ; return airflow dip indicates that the deformation degree of surrounding rocks affected by mining is greatly reduced, creating a good condition for safety production.